Question

5 moles of A reacts with 20 moles of B. Calculate no.of. moles of C and find the limiting reagent
A + 2B =C

Answer 1

Answer:

Limiting reagent is A

As we know that by the eqn given

1mole of A reacts with 2 mole of B

so

5mol of a should react with 2×5=10 moles but there we have 20moles of B so A will finished firsts and limits the reaction

the left 10mole of B left unreacted only 10 mol of B is reacted with 5 mol of B

Answer 2

Answer:

5 moles of C, A is limiting reagent

Explanation:

A + 2B = C

In above reaction 2 moles of B requires 1 mol of A to produce 1 mol of C

Multiply 10 on both the sides of reaction

10A + 20B = 10C

So, 20 moles of B requires 10 moles of A to form 10 moles of C, but it is given that we have only 5 moles of A. So, limiting reagent is A

Multiply both sides of reaction by 5

5A + 10B = 5C

5 moles of A requires 10 moles of B (we already have 20 moles of it, an excess reagent) to produce 5 moles of C

Hence, number of moles of C formed is 5